CentOS 6 support

introspection/bps.c

@@ -11,6 +11,11 @@
 
 #include "libbpf.h"
 
+// TODO: Remove this when CentOS 6 support is not needed anymore
+#ifndef CLOCK_BOOTTIME
+#define CLOCK_BOOTTIME 7
+#endif
+
 static const char * const prog_type_strings[] = {
  [BPF_PROG_TYPE_UNSPEC] = "unspec",
  [BPF_PROG_TYPE_SOCKET_FILTER] = "socket filter",

src/cc/libbpf.c

@@ -48,6 +48,9 @@
 #include "libbpf.h"
 #include "perf_reader.h"
 
+// TODO: Remove this when CentOS 6 support is not needed anymore
+#include "setns.h"
+
 // TODO: remove these defines when linux-libc-dev exports them properly
 
 #ifndef __NR_bpf
@@ -74,6 +77,11 @@
 #define PERF_FLAG_FD_CLOEXEC (1UL << 3)
 #endif
 
+// TODO: Remove this when CentOS 6 support is not needed anymore
+#ifndef AF_ALG
+#define AF_ALG 38
+#endif
+
 #define min(x, y) ((x) < (y) ? (x) : (y))
 
 static int probe_perf_reader_page_cnt = 8;

src/cc/ns_guard.cc

@@ -21,6 +21,9 @@
 
 #include "ns_guard.h"
 
+// TODO: Remove this when CentOS 6 support is not needed anymore
+#include "setns.h"
+
 ProcMountNS::ProcMountNS(int pid) : target_ino_(0) {
  if (pid < 0)
  return;

src/cc/setns.h

@@ -0,0 +1,12 @@
+// This file is only needed to support build for CentOS 6
+// Remove it when no longer needed.
+// File is trivial and therefore is in public domain.
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#define setns(FD, NSTYPE) syscall(__NR_setns, (int)(FD), (int)(NSTYPE))